1. Field of the Invention
The present invention relates to a card connector unit for accommodating a small memory card or what is known as an SD card and connecting a group of external connection terminals provided on this card to an electronic circuit provided in an electronic device, such as a personal computer (PC) and more particularly to a card connector unit compatible with two types of cards differing in length from each other.
2. Description of the Related Art
Cards that can be freely inserted or withdrawn from an electronic device such as a PC or an electronic camera and permits writing or reading of information (hereinafter referred to as SD cards) are already known according to the prior art. This kind of card is substantially rectangularly shaped, and at one end of one side are arrayed a plurality of external connection terminals. The electronic device to accommodate such SD cards is provided with a circuit board on which are mounted required electronic circuits and a card connector unit for connecting the group of external connection terminals mounted on the SD card to the electronic circuits.
Such a card connector unit is provided with a housing having an accommodating space into which the SD card is to be inserted through an inlet, a plurality of terminal pieces fixed to this housing and exposed in the accommodating space, and a discharging mechanism for discharging an accommodated SD card.
The housing is usually configured by combining a frame made of an insulating material and a cover made of a metallic material or an insulating material, and an SD card accommodating space is formed between the frame and the cover. Each terminal piece is provided with a contact exposed within the accommodating space to be able to come into contact with the connection terminals of an SD card and a soldering portion to be soldered onto an electronic circuit provided in an electronic apparatus such as a personal computer (PC). It is so designed that, when an SD card inserted into the accommodating space is placed in a prescribed position, the group of its external connection terminals come into contact with the contact of each terminal piece.
A discharging mechanism of a known configuration, for instance, comprises a slider capable of reciprocating in engagement with an SD card, coil springs elastically energizing this slider in the direction of discharging the card, and engaging pins guided along a heart-shaped cam groove. When the operator presses with fingers the SD card placed in a prescribed position, on the edge toward him or her (rear edge), this configuration, by causing the slider and the engaging pin to work in conjunction, enables the card to move together with the slider outward to the operator""s side to be readily discharged. Another known configuration is such that, by operating a member for discharging action to release the SD card engaged in a prescribed position, the card can be discharged.
Incidentally, in connection with a recently rising call for the usability of an SD card not only as a mere recording medium but also as a communication device by providing it with a transmitter/receiver circuit or the like, the emergence of a new type SD card extended in length but the same in terminal specification as the conventional SD card is expected.
However, since the conventional card connector unit does not have a structure to accommodate such a long SD card, if the SD card is inserted for intended electrical connection, the SD card will substantially protrude outward from the inlet of the accommodating space of the housing, but it will be impossible to insert the SD card more deeply. Thus, if it is tried to adapt a conventional card connector unit to a longer than usual SD card, not only will the appearance of the unit holding such an SD card be awkward but also it will result in serious inconvenience for use because the electronic apparatus such as a laptop PC will have to be carried with the SD card kept inserted in the connector unit.
The present invention has been attempted to obviate these disadvantages of the prior art, and to provide a more convenient card connector unit allowing ready placement of either of two types of SD card differing in length from each other.
In order to achieve the object stated above, a card connector unit according to the invention comprises a housing having an accommodating space into which a card (SD card) provided with a group of external connection terminals is inserted from a side of an inlet, and a first terminal section and a second terminal section fixed to the housing and arranged in the accommodating space with positional discrepancy between them in a depthwise direction, wherein a first accommodating position and a second accommodating position differing in an extent of insertion of the card into the accommodating space are set, wherein the group of external connection terminals are in contact with the first terminal section when the card is placed in the first accommodating position, and wherein the group of external connection terminals are in contact with the second terminal section when the card is placed in the second accommodating position.
A connector unit of such a configuration, if, for instance, the second accommodating position is set farther inward than the first accommodating position, can not only use a shorter SD card placed in the first accommodating position but also a longer card placed in the second accommodating position. Thus, for the longer SD card, there is available an accommodating position in which the card can be inserted deeply to be used, so that the SD card, when in place, does not significantly protrude outward, and accordingly there is no fear of ruining the external appearance or the portability of the connector unit.
If, in the above-described configuration, the first terminal section and the second terminal section have an equal number of terminal pieces arranged along a widthwise direction of the card inserted into the accommodating space, and the respectively matching terminal pieces of these first and second terminal sections are electrically connected to each other, it will suffice to connect terminal pieces on only one side to an external circuit (an electronic circuit provided on the electronic apparatus per se), and the task of fitting the connector unit to the electronic apparatus per se can be simplified. In this case, if respectively matching terminal pieces of the first and second terminal sections comprise mutually connected, integrated units made of metal sheets, and part of these integrated units has soldering portions for soldering onto an external circuit, the first and second terminal sections can be easily formed by pressing, and their fixing to the housing can be easily accomplished by insert molding, resulting in facilitated manufacturing of connector units.
Further, if, in the above-described configuration, the first and second accommodating positions are set so that, for two types of the SD cards differing in length in an inserting/discharging direction, an extent of an external protrusion of a shorter one of the SD cards out of the inlet when placed in the first accommodating position is made substantially equal to an extent of an external protrusion of a longer one of the SD cards out of the inlet when placed in the second accommodating position, the two states will look similar and accordingly neater in external appearance, resulting also in enhanced convenience for use.
Further, if, in the above-described configuration, there are provided a first discharging mechanism for shifting the card placed in the first accommodating position in the discharging direction and a second discharging mechanism for shifting the card placed in the second accommodating position in the discharging direction, each of the first and second discharging mechanisms being provided with a sliding member capable of reciprocating in the depthwise direction, an engaging pin shifting along a heart-shaped cam groove along with shifting of the sliding member, and an energizing member for elastically energizing the sliding member in the discharging direction of the card; wherein, when the card is placed in the first accommodating position or the second accommodating position, the engaging pin of the matching one of the discharging mechanisms is engaged with a pin engaging portion of the heart-shaped cam groove to inhibit shifting of the sliding member, and wherein by pressing the card deeper in the accommodating space in such a state and thereby disengaging the engaging pin from the pin engaging portion, the card is shifted in the discharging direction along with shifting of the sliding member, then the operator can discharge the SD card merely pressing the card, placed in either the first accommodating position or the second accommodating position. Therefore, the operating ease is enhanced when the card is to be discharged, and there will be no need to provide a special operating member for discharging use.